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complicated in complex terrain. Liu et al. (2008) conducted an interrange comparison of the model analyses and forecasts of five U.S. Army test and evaluation command ranges over a 5-yr period. They concluded that forecast errors vary from range to range and season to season. They also found that larger errors are typically associated with complex terrain. Zhong and Fast (2003) compared three mesoscale numerical models and evaluated the simulations over the Salt Lake Valley for cases influenced by
complicated in complex terrain. Liu et al. (2008) conducted an interrange comparison of the model analyses and forecasts of five U.S. Army test and evaluation command ranges over a 5-yr period. They concluded that forecast errors vary from range to range and season to season. They also found that larger errors are typically associated with complex terrain. Zhong and Fast (2003) compared three mesoscale numerical models and evaluated the simulations over the Salt Lake Valley for cases influenced by
the assimilation cycles or assimilation window, a final analysis is produced that provides the initial condition for a subsequent model forecast. When the initial condition is based on an analysis at a single time, and especially when the analysis background is from the forecast of a different model, the subsequent forecast is often referred to as “cold starting” from such initial conditions. No matter how the initial conditions are derived, for mesoscale and storm-scale NWP, they should contain
the assimilation cycles or assimilation window, a final analysis is produced that provides the initial condition for a subsequent model forecast. When the initial condition is based on an analysis at a single time, and especially when the analysis background is from the forecast of a different model, the subsequent forecast is often referred to as “cold starting” from such initial conditions. No matter how the initial conditions are derived, for mesoscale and storm-scale NWP, they should contain
120 WEATHER AND FORECASTING VOLUME?FORECASTER'S FORUMOn the Use of Mesoscale and Cloud-Scale Models in Operational ForecastingHAROLD E. BROOKS, CHARLES A. BOSWELL III, AND ROBERT A. MADDOXNOAA /National Severe Storms Laboratory, Norman, Oklahoma27 August 1991 and 8 November 1991 In the near future, the technological capability will be available to use mesoscale and cloud
120 WEATHER AND FORECASTING VOLUME?FORECASTER'S FORUMOn the Use of Mesoscale and Cloud-Scale Models in Operational ForecastingHAROLD E. BROOKS, CHARLES A. BOSWELL III, AND ROBERT A. MADDOXNOAA /National Severe Storms Laboratory, Norman, Oklahoma27 August 1991 and 8 November 1991 In the near future, the technological capability will be available to use mesoscale and cloud
. 2010 , 2013 ), the cases are still limited to ascertaining the effects of storm-induced sea surface cooling on TC intensity forecast skill in the vicinity of Japan. In this study, we conduct a large number of 3-day forecast experiments around Japan in order to obtain a reliable TC intensity forecast assessment. This is achieved by running a JMA nonhydrostatic atmospheric mesoscale model (AMSM) that is similar to an operational regional model and an atmosphere–ocean coupled mesoscale model (CMSM
. 2010 , 2013 ), the cases are still limited to ascertaining the effects of storm-induced sea surface cooling on TC intensity forecast skill in the vicinity of Japan. In this study, we conduct a large number of 3-day forecast experiments around Japan in order to obtain a reliable TC intensity forecast assessment. This is achieved by running a JMA nonhydrostatic atmospheric mesoscale model (AMSM) that is similar to an operational regional model and an atmosphere–ocean coupled mesoscale model (CMSM
events, and important questions remain. What is the relative importance of surface fluxes and downslope flow in thermal trough formation and evolution? Does advection play a significant role? Such issues will be addressed in this paper. Specifically, this manuscript will describe the synoptic and mesoscale evolution of a representative WCTT event that occurred on 13–16 May 2007 using observations and simulations from the Weather Research and Forecasting (WRF) Model. This event is similar to the
events, and important questions remain. What is the relative importance of surface fluxes and downslope flow in thermal trough formation and evolution? Does advection play a significant role? Such issues will be addressed in this paper. Specifically, this manuscript will describe the synoptic and mesoscale evolution of a representative WCTT event that occurred on 13–16 May 2007 using observations and simulations from the Weather Research and Forecasting (WRF) Model. This event is similar to the
LAPS within the OWSS was important. For the first time, a mesoscale forecast model initialized with comparably high-resolution analyses was implemented in an operational environment using technology representative of that planned for NWS forecast offices in the next several years. The LAPS forecasts were produced by the Regional Atmospheric Modeling System (RAMS) ( Pielke et al. 1992 ; Walko et al. 1995 ) developed at Colorado State University. The operational forecaster interactively selected
LAPS within the OWSS was important. For the first time, a mesoscale forecast model initialized with comparably high-resolution analyses was implemented in an operational environment using technology representative of that planned for NWS forecast offices in the next several years. The LAPS forecasts were produced by the Regional Atmospheric Modeling System (RAMS) ( Pielke et al. 1992 ; Walko et al. 1995 ) developed at Colorado State University. The operational forecaster interactively selected
) and Mesoscale Eta Models (MESO; Black 1994 ), the National Center for Environmental Prediction’s (NCEP’s) most complex synoptic model and first mesoscale model, respectively, produce high-resolution output at 30–50 vertical levels and at every forecast hour in the form of soundings (or“profiles”). Therefore, the fine time and spatial resolutions of the model output make possible operational prediction of mesoscale features unlike what has been possible previously. The forecasting problem is how
) and Mesoscale Eta Models (MESO; Black 1994 ), the National Center for Environmental Prediction’s (NCEP’s) most complex synoptic model and first mesoscale model, respectively, produce high-resolution output at 30–50 vertical levels and at every forecast hour in the form of soundings (or“profiles”). Therefore, the fine time and spatial resolutions of the model output make possible operational prediction of mesoscale features unlike what has been possible previously. The forecasting problem is how
1. Introduction Extreme precipitation, and the flooding and flash flooding it can cause, remains a particularly challenging prediction problem for numerical models and human forecasters (e.g., Fritsch and Carbone 2004 ; Novak et al. 2011 ). This stems in part from the small-scale, chaotic nature of the deep convection that is responsible for producing the heavy rainfall (e.g., Zhang et al. 2003 ) and the insufficient density of observations at the mesoscale (e.g., Dabberdt et al. 2005
1. Introduction Extreme precipitation, and the flooding and flash flooding it can cause, remains a particularly challenging prediction problem for numerical models and human forecasters (e.g., Fritsch and Carbone 2004 ; Novak et al. 2011 ). This stems in part from the small-scale, chaotic nature of the deep convection that is responsible for producing the heavy rainfall (e.g., Zhang et al. 2003 ) and the insufficient density of observations at the mesoscale (e.g., Dabberdt et al. 2005
forecasts for Europe . Bull. Amer. Meteor. Soc. , 94 , 1393 – 1405 , https://doi.org/10.1175/BAMS-D-12-00099.1 . 10.1175/BAMS-D-12-00099.1 Rutledge , S. A. , and P. V. Hobbs , 1983 : The mesoscale and microscale structure of organization of clouds and precipitation in midlatitude cyclones. VIII: A model for the “seeder-feeder” process in warm-frontal rainbands . J. Atmos. Sci. , 40 , 1185 – 1206 , https://doi.org/10.1175/1520-0469(1983)040<1185:TMAMSA>2.0.CO;2 . 10
forecasts for Europe . Bull. Amer. Meteor. Soc. , 94 , 1393 – 1405 , https://doi.org/10.1175/BAMS-D-12-00099.1 . 10.1175/BAMS-D-12-00099.1 Rutledge , S. A. , and P. V. Hobbs , 1983 : The mesoscale and microscale structure of organization of clouds and precipitation in midlatitude cyclones. VIII: A model for the “seeder-feeder” process in warm-frontal rainbands . J. Atmos. Sci. , 40 , 1185 – 1206 , https://doi.org/10.1175/1520-0469(1983)040<1185:TMAMSA>2.0.CO;2 . 10
1996 ; Marchok et al. 2007 ), or African easterly waves ( Céron and Guérémy 1999 ) are essential to accurate QPFs over the specific regions. Examining numerical forecasts of MPs is important so that additional contributions to QPF errors for progressive MCSs can be identified. The purpose of this study is to evaluate the forecasts of MPs and their associated rainfall in the National Centers for Environmental Prediction’s (NCEP’s) operational North American Mesoscale (NAM) model. Evaluation of
1996 ; Marchok et al. 2007 ), or African easterly waves ( Céron and Guérémy 1999 ) are essential to accurate QPFs over the specific regions. Examining numerical forecasts of MPs is important so that additional contributions to QPF errors for progressive MCSs can be identified. The purpose of this study is to evaluate the forecasts of MPs and their associated rainfall in the National Centers for Environmental Prediction’s (NCEP’s) operational North American Mesoscale (NAM) model. Evaluation of
